Macitentan(Actelion) success in Phase III for PAH - 01-May-2012

Initial analysis indicates that the pivotal, long-term, event-driven study SERAPHIN with macitentan, a novel dual endothelin receptor antagonist from Actelion, in 742 patients suffering from Pulmonary Arterial Hypertension (PAH) and treated for up to three and a half years, has met its primary endpoint. SERAPHIN is the largest randomized, controlled study in PAH patients with a long-term treatment to include a clearly defined morbidity/mortality primary end-point. The pivotal Phase III study showed macitentan, at both the 3 mg and 10 mg dose, decreased the risk of a morbidity/mortality event over the treatment period versus placebo. This risk was reduced by 45 percent in the 10 mg dose group (p<0.0001). At 3 mg, the observed risk reduction was 30 percent (p=0.0108). Treatment with macitentan in the SERAPHIN study was well tolerated. Full results are to be presented at a future scientific meeting. Tracleer (bosentan) the prime Actelion drug for PAH faces patent expiry in 2015.